Device for phonographs with linear phonogram carriers



. Jan. 11, 1938. H.VO'GT ET AL Re: 20,621

DEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGRAM CARRIERS Original FiledMarch 20. 192 :5 Sheets-Sheet 1 [rave 1650);; V09! F 2 J Alaska/Jew lg-11m H. VOGT ET AL Jan. 11, 193s.

. DEVICE FOR PHONOGRAPHS WITH LINEAR FHONOGRAM CARRIERS Original FiledMarch 20, 1922 3 Sheets-Sheet 2 Jan. 11, 1938. H voG-r A Re. 20,621

DEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGRAM CARRIERS on mal Filed March2 1922 I 3 Sheets-Sheet :5

WITNESSES 1N VENTORS I .Jow /wh oae.

y J' ef17% 'ATTORNEYS Reissued Ja n-11 1938 UNITED STATES PATENT OFFICEDEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGBAM CARRIERS Hans Volt, Berlin-Steglitl, Joseph Massolie, Berlin-Ghenicke, and Josef Engl, Be

Germany, assignors, by means aslottenburg, signmen rim-Charis, toAmerican 'lrl-Ergon Corporation, New York, N. Y., a corporation of NewYork 6 Claims. (cl. 214-) The recording and the reproduction of soundwaves by the use of linear phonogram carriers such as film strips, canonly be effected in absolutely satisfactory manner, even after the re- 5moval of all otheroccurring difilculties, when the speed of the-recordcarrier is.uniform both for the receiving and the reproduction, and whenin both cases no variations of any kind occur. Especially in the case ofmusical reproductions is the record extremely sensitive to the slightestvariations of speed. Consequently, it has hitherto been usual to provideapparatuses such as phonographs and gramophones witth speed regulators.In these apparatuses, however, the problem of the uniform a motion doesnot assume the same importance as in the case oi sound recording orreproducing apparatus embodying linear 'phonogram carriers, such asphotographic sound records on film strips or ribbons because with theformer the record carrier consists of a cylinder or disc possessing asomewhat considerable momentum when the desired velocity is impartedthereto which equalizes any small irregularitiesin the motion, such asmay be caused, for instance, by-the' driving mechanism. In the lattercase, however, that of phonographs with linear records, such as filmstrips, the portion of the record which is active at a given momentpossesses practically no momentum to be taken into consideration.irregularities in the motiomsuch, for instance, as may be caused by theprojections, the teeth, the,belts, the connecting places, and so forth,or by the friction, at the guiding point, become consequently very muchmore important with these-and thus greatly impair the periodicity ofthesound recorded. I

According to the present invention, this drawback which attaches to allhitherto known propulsion mechanisms for linear phonogram records isobviated by the arrangement, that the light sound record has given to itat the controlling point the property of. a weighty mass. This isattained by the arrangement that the record carrier (a film strip or thelike) is firmly pressed against one or more rollers connecting with aheavy rotating mass, so that the 'record moves in exact conformity withthe rollers and the rotating mass.

Also, according to the present invention a dependable and highlyefflcient optical system is provided for use in conjunction with movingfilm strips of the above indicated character.

Various further and also various more specific objects, features andadvantages will more clearly appear from the detailed description givenbelow taken in connection with the accompanying drawings, which form apart of this specification.

The invention consists insuch novel features, arrangements .andcombinations of parts and methods as may be shown, described and claimedin connection with the embodiments of the invention herein disclosed bywayof example only.

constructional examples of the invention are illustrated in the figures,in which:-

Figure 1 is a side elevation of a linear phonogram carrier.

Figure 2 is a side elevation of a modified form of phonogram carrier,

Figure 3 is a longitudinal section of another form of phonogram carrier.

Figure 4 is an end view of the form of carrier shown in Figure 3.

Figure 5 is a view in elevation of a fly wheel showing an elasticcoupling adaptable to the rear side of the fly wheels, the face views ofwhich are shown in various of the other figures.

Figure 6 is a vertical section 01' the same.

Referring to Fig. 1, partially illustrating sound reproducing apparatus,the phonogram carrier, which in these illustrations'is shown as a filmstrip bearing a photographic sound record, moves over the rollers r, r,suitably coupled by gearing or belting, of which rollers preferably theroller 1" ,directly driven bythe motor is provided with teeth. One oreven both rollers are rigidly connected with rotating masses as at m,m", whichgive to the film strip f travelling between them under tensionthe requisite uniformity of its motion. Between the rollers 1", 1'',there is placed preferably in a casing h thelight-sensitive cell 2sensitive to electric light, which is influenced by a light my passingfrom a light source (not shown), through objective 0, and then throughthe film. The rollers or idles dr, (11'', press the film against thecarrier roller r Another construction of theinvention is shown in Fig.2, in which the little irregularities of movement often caused by thefeeding of the film by the teeth on roller r, in the Fig. 1construction, or which are caused by the mechanical vibrations of thestretches of film between rollers r and 1 in the Fig. 1 construction,are avoided.

The film f is drawn by the sprocket V to the controlling point r and isremoved from the con-- trolling point bythe sprocket V. Between thesefeeding sprockets, the film is guided over the periphery of a largerroller R on which it, rests closely by friction, even during the turningmotion. As the roller is rigidly connected with the rotating mass m, orcan be constructed so as to be itself the rotating mass, the film movesuni-' formly on in like manner as the surface of the roller R. For thepurpose of pressing the film upon the roller R, and for theequalizing'of irregularities of motion, there are provided thespring-supported rollers 'dr', dr'. That is, the

spring pressed rollers engaging the film at points between the feedingrollers and the fiy wheel roller, thus exert resilient pressure againstthe film to force the film into effective engagement with the flywheeland thereby at the same time the film is deflected from a straight lineposition,,

. sound record on the film, the light rays pass through the film stripand fall upon the photo cell z preferably placed in the interior ofroller,

R. For thispurpose, the roller is either partially transparent, made ofglass, for example, or the part of the film bearing the sound recordprojetlztes beyond the non-transparent parts of the ro r. l

In the hereinbefore described form of execution of the invention thedriving of the film sound record is however not efiected directly at thePoint of projection but in front or behindthe same. The driving point ofthe film can however, in a further development of the invention.

' be arranged directly at the point at which light is projected throughthe record. The driving member can, in this case, be constructed in sucha manner that the engaging and disengaging, of the feeding teeth of thefilm-feeding sprocket with the perforationsof the film, will not affectthe speed of the film at the projection point, i. e., at the point atwhich light falls upon the film in recording, or at which it passesthrough the film in reproducing.

.l lgures 3 and 4 'show this form of construction by way of example. Theshaft a journalled at b and c, carries at one end the feeding-cylinder dwhich has the customary teeth designed to engage with the perforationsof the film, The film I is in contact with one part of the circumferenceof this cylinder, the length ofv this part corresponding with thedistance between the pressure rollers e and 9. Fig. 4. The drivingmember 1: such as a gear for example, and also the fiy wheel 1, arekeyed upon this shaft and designed to communicate to the shai'tandconsequently to the cylinder 41, a uniform-revolving speed. The filmwillconsequently move also with unlformjspeed, for instance in the direction9-e. These rollers e-a press the film strip firmly against thecylinderit so that it lies, without possibility ct being shifted, upon theentire peripheral length of cylinder :1 from g to e. because-oi the feedteeth of cylinder d engaging with the perforations of the film. I Theengagement and disengagement of the feed teeth on cylinder d, with theperforationsof the film, takes place under the pressure of the rollers gand c, Fig. 4, so that vibrations or Jerky motions of the film band, dueto such tooth engagement or disengagement, no

- longer make themselves felt at the point of light projection throughthe same. The free ends 1-! of the film band are preferably guided byrollers (not shown) for preliminary winding up in the manner well knownin picture cinematography. so that they form a loop.

'It will be understood that the invention is intended particularly foruse in connection with transparent film records, onwhich-sound isrecorded photographically. by causing acoustically modulated light toact upon the film at the control' point. Also that, in reproducing,-light passes through the sound record on the film at the control point,and falls' upon the photo-cell z to set up currents corresponding, infrequency variations, to the sound record through which the light haspassed. Also, that the film may pass from a supply reel on which-it iswound, at the starting end, to a reel on which it is progressivelywound, at thefinal end, as is usual in cinematography. Further, that thefilm contemplated may be a talking moving picture film, con-- tainingpictures in addition tothe sound record. Sucha record must be fedintermittently past the point at which the pictures are recorded on thefilm. or at which the projection light shines through the pictures inreproducing. In addition there is need of feeding the film uniformlypast the point at which the sound is recorded or reproduced. For suchfilm the loop referred to is preferably formed, between the point ofintermittent feed for picture recording or projection, and the point ofuniform motion for sound recording or reproducing, the production ofsuch loops in the film being common in cinematography.-

For recording purposes a solid cylinder or roller may be employed inplace of the .roller d upon'which the full width of the film strip willbear, sincein recording the acoustically modulated light which is to berecorded need not pass through the film butonly need act upon the,

stance the cell 2 with the cathode l and. anode p.

The cylinder or roller :1 in Figure 3 shows a form ofconstruction bywayof example in which the part of the film which carries. the soundrecordprojects beyond the edge of the cylinder. The

light collected by the object. glass 0 to a narrow line, comes from asuitablefknown means or source of light projection so arranged. asln'db,

cated for example by the dotted lines in Figs. 3

and 4; that the converged narrow ,line of light is substantially focusedor impinges upon the Hares. of translation t on thefilm as a linerunning transversely of the direction of movement. of the film The soundrecord as indicated in Fig. 3 may be located at the outer side of onerow of perforations in the film. The sound record markings can, however,if desired, be located between the two rows of perforations in the film,in which case only one row of perforations would be utilized for feedingthe film, these perforations being engaged by the teethon roller dnearest to the center of cell z. In this .case the sound record portionsof the film would still overhang the edge of roller d, the faroverhanging edge of the film, moving along either without a specialguidance or running over a roller with or without feeding teeth, whichroller may be an idler or may be.

specially driven, as desired.

Another feature may advantageously be incorporated in the invention. Ifthe driving shaft of the tone-film revolves with a low number ofrevolutions andif a rigid drive is used, the-cincumferential speed offly wheels which can be practically utilized, will, under certainconditions; not be sufficient for compensating the speed fluctuations.

According to the invention the driving of the fly wheel axle istherefore effected with the aid of an elastic coupling, for instance aspring.

This spring can be very feeble as, at constant speed, .it has toovercome only the losses from friction of the drivenpart. As however, atthe starting and stopping of the driving mechanism, the inertia of thefiy wheel'has to be overcome, it is advantageous to limit the play ofthe spring in either direction by a fixed stop.

Figures 5 and 6 show such a form of execution by way of example. Theaxle l of the wheel with the rotating mass i is separate from thedriving shaft (1. Upon the latter a lever 2 is arranged which drives therotating mass through the intermediary of the spring 8 and of the stud Ifixed to the fiy wheel. The studs I which are also fixed on the fiywheel limitthe stroke of the lever Lat the starting and at the stoppingso that the spring 3 is protected againstexcessive tension and againstjumping out of position.

While the invention has been described in de- I tall with respect tocertain particular preferred examples which give satisfactory results,it will be understood by those skilled in'the art after understandingthe invention that various changes and modifications-may be made withoutdeparting from the spirit and scope of the invention.

and it is intended therefore in the appended claims to cover all suchchanges and modifications.

We claim:-

1. An apparatus for reproducing speech, music or the like sounds fromvibrations recorded on a film strip, comprising a photoelectric cell,means for imparting to the film an arcuate, rapid and uniform motionlongitudinally of the film past,

said cell, a source of light projection for'providing a line oflight infixed position for translating the sound from the film strip r'novinguniformly past said light, 'and an objective lens in the neighborhoodofthe area of translation on the film strip but spaced, therefrom forcollecting said projected light and directing the same as a convergingnarrow line extending transversely. of

the direction of movement of the film strip and.

passing through the area of translation on the fill; and to said cell.

In combination, optical means for translating sound vibrations to .orfrom a film record strip by the use of light varied in accordance withthe sound,-a' constant speed film feeding xfilm as fed by said feedingroller, said compensating means including a spring pressed rollerengaging the film at a point between said feeding roller and saidflywheel roller with a resilient pressure causing the film to bedeflected a variable amount in passing over said spring pressed roller,the extent of suchdefiection varying with said irregularities of motion.

3. In combination, optical means for translating sound vibrations to orfrom a film record strip.

by the use oflight varied in accordance with the sound, a constantspeedfilm feeding mechanism for moving the film strip uniformly pastsaid light, comprising a continuously rotating feeding roller, aflywheel, a. roller over which the film passes and which roller isoperatively connected to said flywheel, means to compensate forvariations in the motion of the film arising from small irregularitiesin the motion of the film as fed by, said feeding roller, saidcompensating means including a member yieldingly pressing against thefilm at a. point between said feedingroller and said flywheel roller tovariably deflect the film from a straight line path at such point.

strip, the combination are cylinder, a flywheel i therewith, means forrotating said cylinder at uniform speed under control of said flywheel,means for feeding the film record strip onto said cylinder at one pointand off therefrom at another point and causing the film strip to adhereclosely to the cylinder without'slippage between said points, said filmrecord strip being arranged to overhang one end of the cylinder, 9.photo-electric cell positioned inwardly of the overhanging portion ofthe film, and means for directing light through said overhanging portiononto said photoelectric cell whereby sound'is translated by the lightfrom the film strip moving uniformly past said light.

5'. An apparatus for reproducing speech, music or the like sounds fromvibrations recorded on a film strip, comprising a photoelectric cell,means for imparting to the film an arcuate, rapid and uniform motionlongitudinally of the film past said cell, a source of light projectionfor providing a line of light in fixed position for translating thesound from the film strip moving uniformly past said light, and anobjective lens in the neighborhood of the area of translation on thefilm strip but spaced therefrom for collecting said projected light anddirecting the same as a converging narrow line extending transversely ofthe direction of movement of the film strip and passing through the areaof translation on the film and to said cell, said means including aflywheel and means operatively connecting said flywheel with the film,which last named means ime parts uniformity of motion of the flywheel tothe film in passing through said lineof light.

fi. An apparatus for translating sound vibrations representative ofspeech, music or the like, to or from a film record stripby the use of aline of light varied in accordance with the sound, which comprises meansfor imparting to the film an arcuate, rapid and uniform motionlongitudiretaining the moving film under tension at the areaoitranslation, :1. source of light projection for providing a. line orsaid light in fixed position, and an objective lens in the neighborhoodor said area 01' translation on the film but spaced there- 'Irom forcollecting said projected light and directing the same as a convergednarrow line impinging dirwtly upon the arcuately moving film 10 at saidarea .of translation and transversely of 20,621 nally 61 the film pastsaid u e of 1mm, and for the direct on of movement of the film, saidmeans HANS VOGT. OSEPH MASSOLLE'. J OSEF ENGL.

